Lallana, signed for £25 million from the Saints as Liverpool attempted to fill the void left by Luis Suarez's move to Barcelona, scored the opening goal in a patchy 2-1 home win over West Bromwich Albion in the Premier League.
All the talk before kickoff was of their mercurial Italy striker Mario Balotelli being left among the substitutes after a similarly disappointing start to his Anfield career.
While manager Brendan Rodgers will have plenty of hard thinking to do as to how to get the best out of Balotelli, he will not be having too many sleepless nights over Lallana.
In his first five Liverpool appearances, only one of which ended in victory, Lallana had looked slightly uncomfortable with the pressure of such a big price tag.
But with Balotelli benched, Daniel Sturridge still injured and Suarez now a fading memory, the England international took responsibility on Saturday, producing a goal of real quality that had Rodgers purring his appreciation.
Playing a one-two with Jordan Henderson seconds before the break, Lallana produced a superb finish to silence the grumbles from the home fans who have seen their side regress since last season's runners-up finish to Manchester City.
"It was a wonderful goal. I thought he was very, very good today and his intensity and work rate in the team was exceptional. He showed his quality," Rodgers, who gave a first Premier League start to Lallana's former Southampton team mate Rickie Lambert in place of Balotelli, told reporters.
WONDERFUL PLAYER
"You saw the supporters' reaction to him, I think they really appreciate what he is trying to give the team.
"I'm delighted for him. He's a wonderful, technically-gifted player and works very, very hard. He scored a wonderful goal, which is what we needed."
Liverpool, who moved up to sixth place with the win, were not entirely convincing though and were pegged back when Saido Berahino converted a spot kick 10 minutes after the restart.
West Brom looked capable of adding to Liverpool's woes - the Anfield side had lost two and drawn one of their previous three league games - before the impressive Henderson clipped in the winner.
Lambert's afternoon did not go as planned with the local lad missing a couple of good chances and eventually being replaced by Balotelli late on.
"Rickie is desperate to score for Liverpool," Rodgers said.
"He'll probably be disappointed with one or two of the opportunities he had today.
"But I know with Rickie that I have a real honest professional who wants to die for Liverpool. He wants to give everything he has for the club and there will be times this year when we'll need that."
